Circuit breaker



Aug. 7, 1945. H. L. PEEK ETAL CIRCUIT BREAKERS Filed June 5, 1942 7 3 25 5 Z 8 W, A Z 5 7 a w 4 W 8 A INVENTORS. 23/11 Peek .6

fl (awn/hi. ATTORN Z. I n S m a 0/ i a fi WQTNESSES:

f n/kw Patented Aug. 7, 1945 CIRCUIT BREAKER Henry L. Peek, Camp Gordon;Ga., and James M.

Cumming, Turtle Creek, Pa., assignors to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication June 5, 1942, Serial No. 445,880

16 Claims.

The invention relates to circuit breakers and more particularly tocircuit breaker operating means of the fluid or gas pressure type.

In designing compressed air or gas operating means for circuit breakers,a combination of operating gas or air pressure and operating piston areamust be selected which will develop suflicient power to overcome thecontact load of the breaker which is picked up during the latter portionof the closing stroke. In many types of breakers the contact load is ofvery considerable magnitude due to the contact pressure springs. Also ifthe circuit breaker is to be used for quick automatic reclosing servicethe operating means must develop suflicient power to quickly reverse themovement of the breaker before the full open position is reached andreclose the breaker at high speed. If the large driving force requiredfor these conditions is applied during the first part of the closingstroke on normal closing opnumber of times after the power from thecompressor motor fails.

An object of the present invention is the provision of a circuit breakerwith'a fluid pressure operating means embodying automatic means whichwill automatically change the rate at which fluid is supplied to theoperating mechanism in response to a change in magnitude of the fluidpressure in a portion of the fluid pressure supply erations or onautomatic reclosing operations started when the breaker is at rest inthe full open position, the breaker may be operated at such a high speedand the kinetic energy developed may be so high as to producedestructive slamming. The copending application of H. L. Peek, SerialNo. 445,733, filed June 4, 1942 and assigned to the assignee of thepresent invention, discloses and claims a compressed air circuitbreakeroperating means embodying an automatic means which is effectiveto admit compressed air to the mechanism at a predetermined rate duringthe first part of closing operations started from the full open positionto prevent slamming, and

which is automatically operable during the latter I portion of theclosing stroke and also during quick enough to close the breaker at allwhen the source pressure dro s. If this condition exists the mechanismwill either fail to close the breaker or will 'close too slowly. Alsoonly a relatively small number of operations will be possible. withoutrecharging the main reservoir. It is very desirable that a mechanismwill be able to operate a given system.

Another object of the invention is the provision of a circuit breakerwith a fluid pressure operating mechanism embodying means responsive tothe fluid pressure in a portion of the fluid pressure supply system forautomatically providing the proper rate of flow of fluid to themechanism despite changes in fluid pressure in said portion of thesupply system.

An object of the present invention is the provision of a circuit breakerwith a fluid pressure operating means embodying means for automaticallymaintaining the driving power delivered to the operating mechanismsubstantially the same when the fluid pressure in the supply systemdecreases a substantial amount as when the pressure is at normal value.

Another object of the invention is the provision of a circuit breakerwith a compressed gas operating mechanism having means responsive to adecrease in gas pressure in a portion of the compressed gas supplysystem for automatically providing an increased supply of compressed gasto the mechanism over what would be obtained from said portion of thesupply system at the decreased pressure.

Another object of the invention is the provision of a circuit breakerwith a compressed gas operating mechanism havlngautomatic means fordelivering compressed gas to the mechanism at a predetermined rateduring the first part of a closing operation and at anincreased rateduring the latter part of a closing operation and during quick reclosingoperations, and means responsive to a decrease in gas pressure in a por--tion of the compressed gas supply system for automatically providing anincreased supply of "compressed gas to the mechanism over what size ofthe throttle opening as the pressure in the reservoir decreases and forrestoring the throttle opening to normal size when the gas pressure inthe reservoir is restored to normal.

Another object of the invention is the provision of a compressed airoperating mechanism .for a circuit breaker with an automaticallyoperated valve and means responsive to a decrease in the pressure of theair in a portion of the compressed air supply system for automaticallyopening the valve to make up for the decrease in driving power.

Another object of the invention is the provision of a circuit breakeroperating means of the fluid pressure type having an automatic valvemaintained in one position during the first part of closing stroke oi!the operating mechanism starting from the full open position of thebreaker and automatically operated to a wide open position during thelatter part of the closing stroke, and means responsive to the fluidpressure in a portion of the fluid pressure supply system forautomatically opening the valve as the pressure in the reservoirdecreases.

Another object 01' the invention is the provision of a compressed aircircuit breaker operating mechanism having an automatic means includinga valve operative to cause compressed air to be delivered to themechanism at a predetermined rate during the first part oi. the closingstroke starting from the full open position oi' the breaker andautomatically operated to an open position during the latter portion ofthe breaker closing stroke to permit compressed air to flow to themechanism at an increased rate. and means responsive to a decrease inpressure in a portion of the compressed air supply system forautomatically providing for an increased supply of compressed air to themechanism over what would be obtained from said portion of the system atthe reduced pressure.

Another object of the invention is the provision of a circuit breakerwith an improved compressed gas operating means embodying an automaticmeans for delivering the proper amount of power to the mechanism tomaintain proper speed of operation despite variations in operating loadand in the available gas pressure.

Further objects and advantages of the invention will become apparentfrom the following detailed description of one embodiment thereof whenread in conjunction with the accompanying drawing in which:

Figure 1 is an elevational view, partly in section, of a compressed aircircuit breaker operating mechanism embodying the invention, the circuitbreaker being shown schematically;

Fig. 2 is a fragmentary detail sectional view showing the throttle valveas viewed at right angles to the showing thereof in Fig. l; and

Fig. 3 is an enlarged detail sectional view of the device forcontrolling the throttle opening in response to changes in air pressurein the air reservoir.

The present invention constitutes a further development and improvementover the compressed air circuit breaker operating means disclosed in theaforementioned copending application of H. L Peek, Serial No. 445,733,.and the invention is illustrated as applied to the same type 01compressed air operating mechanism.

Referring to the drawing, the circuit breaker represented veryschematically at 1 may be of any conventional construction either of theoil break or air break type. The circuit breaker, as schematicallyshown, comprises stationary coniii) tact means 9 and movable contactmeans Ii. Most conventional circuit breakers usually embody a contactpressure spring construction for maintaining the desired pressureengagement of the contacts in the closed position. The main bridgingcontact is usually backed by springs to secure contact pressure. Thecontact pressure securing means is represented very schematically in thedrawing by the resilient laminated leaf spring construction oi. themovable contact means H.

Although illustrated as a single pole circuit breaker, it will, ofcourse be understood that the breaker may be a multipole circuit breakerhaving a set of contacts 9 and II for each pole thereof with the movablecontacts mechanically connected for simultaneous operation in the usualmanner. The circuit breaker is biased to open circuit position by meansof an accelerating spring shown schematically at l5, and the breaker ismechanically connected to the operating mechanism indicated generally atI! by a suitable connecting means. The connecting means is representedschematically as comprising a lever 19 pivoted at II on a fixed support,one end of the lever being pivotally connected to the breaker lift rod23 and the other end being pivotally connected to an operating rod 25which is, in turn, mechanically connected to the operating mechanismI 1. v

The operating mechanism comprises a main casting 21 which is formed toprovide a cylinder 29 closed at the upper end by an integral part of thecasting. A closure member 3| is secured to the lower end of the cylinder29, this closure member having a relatively large port 33 therein opento the atmosphere. An operating or latching lever 35 is pivotallymounted at one end on the casting 21. The operating lever consists oftwo spaced parallel levers 31 which are pivotally connected at one endby means of a pivot pin 39 to the upper end of a pair of links 4| (onlyone being shown) pivotally mounted on the main casting 21. The free endof the levers 31 comprising the operating lever are connected by a crossmember and carry a short shaft II there between on which is rotatablymounted a latching roller 41 disposed between the levers 31. The breakeroperating rod 25 is pivotally connected by a pivot pin 49 to themid-point of the operating lever 35, the pivot pin extendingtransversely through thelevers 31 and engaging an opening in the lowerend of the rod 25. The breaker operating lever is adapted to be held inclosed position to hold the breaker closed by means of the high speedlatching mechanism comprising a main latch 5| which ispivoted on themain casting 21 by a pivot pin 53. The latch II is adapted to extendbetween the parallel levers 31 and its latch end is adapted to engageand restrain the latching roller 41 carried by the free end of theoperating lever 35. 'The latch II is biased to latching position bymeans of a spring pressed plunger 51. A stop 55 limits clockwisemovement of the latch 5|. An auxiliary latch 81 is provided for normallyengaging and holding the main latch 5! in latching position. Theauxiliary latch 81 is pivoted on the casting 21 by a pivot pin I! andhas a latch projection H adapted to engage under a projection 13 of thelatch ll. A spring 15 biases the auxiliary latch 61 to latchingposition. The auxiliary latch is provided with a projection 11 whichextends directly over the upper end of the trip plunger 19 of anelectromagnetic trip de vice 8|.

The trip device BI comprises, in addition to the trip plunger I9, anE-shaped core 83 of magnetic material, an energizing winding 85 mountedon the center leg of the core and the movable armature 8T cooperatingwith the core 83. The trip plunger I9 is secured to the center portionof the armature 81, and slidably extends upwardly through a guideopening in the center leg of the core 83 and through an opening in thehorizontal portion of the main casting 21. A spring 89 biases thearmature BI downwardly to unattracted position.

When the trip device BI is energized, the armature 81 thereof is movedupwardly against the core 83 causing upward movement of the trip plungerI9. This upward movement of the trip plunger moves the auxiliary latch61 counterclockwise and disengages the projection I3 of the main latch5| whereupon the accelerating spring I5 of the circuit breaker moves thebreaker to open position, the operating lever 35 being rotatedcounterclockwise about its pivoted end by the opening movement of thebreaker. During the initial opening movement of the operating lever 35,the roller 41 pushes the main latch 5| in a counterclockwise directionas it clears the latch. In order to prevent the auxiliary latch 61 fromreturning to latching position until the breaker lever 35 is returned toclosed position, there is provided a U-shaped balance lever 95, the legsof which are pivotally mounted on the extending ends of the pivot pin 69on opposite sides of the auxiliary latch 61. The balance lever 95 isbiased counterclockwise by a compression spring 9! which is seated in arecess in the casting 21 and engages the under side of a projection 99of the balance lever. A cross member IOI on the free end of the balancelever 95 is disposed directly beneath the free end of the operatinglever 35 so that the balance lever will be held down in an inoperativeposition when the operating lever 35 is in closed and latched position.However, when the operating lever 35 is released,'the balance lever 95is rocked counterclockwise and the portion 99 thereof engages and holdsthe auxiliary latch 61 in unlatching position until the breakeroperating lever 35 is returned to its closed position and its roller hasbecome reengaged under the latch face of the main latch 5|. For thispurpose, the biasing spring 9'! is stronger thanthe auxiliary latchspring I5.

An operating piston I03 is reciprocably movable within the operatingcylinder 29, and this piston has a piston rod I01 which slidably extendsin a fluid-tight manner through an opening provided therefor in the topwall of the cylinder 29. The upper end of the piston rod I01 has aconnecting element I09 threadedly connected thereto which is pivotallyconnected to the pivot pin 49 carried by the operating or latching lever35. Thus the operating piston I03 is mechanically connected directly tothe circuit breaker operating rod 25.

The operating piston I03 is adapted to be moved downwardly in thecylinder 29, to close or automatically reclose the circuit breaker, bycompressed air from an auxiliary air reservoir or tank III. thecompressed air being admitted to the upper end of the cylinder 29through an inlet passage I I 2 controlled by a main inlet valveindicated generally at H3. The opening operation of the main inlet valveis controlled by a pilot valve II5 operated by an electromagnet orsolenoid II'I.

Compressed air is stored and maintained at a predetermined normalpressure in the air reservoir I I I from a large main reservoir (notshown) supplied by a conventional motor driven compressor (not shown).

The inlet valve mechanism is of the same construction as that disclosedin the copending application of J. M. Cumming and R. C. Cunningham,Serial No. 410,686, filed September 13, 1941. and assigned to theassignee of the present invention. The inlet valve 3 comprises a valvehousing H9 and a main valve element I2I mounted in the valve housing.The main valve element I 2| is adapted to be operated to open positionby an air actuated valve piston (not shown) upon energization of thevalve controlling electromagnet I I1, and the valve is returned toclosed position by spring means (not shown) upon deenergization of theelectromagnet I H.

In order to provide for quick reversal of movement of the operatingpiston I03 and circuit breaker I to provide the efiect of trip-freeoperation of the circuit breaker, the mechanism is provided with an airpressure exhaust means similar to that disclosed in the above mentionedcopending application, Serial No. 410,686. The air pressure exhaustmeans causes quick collapse of air pressure in the operating cylinderabove the piston I03 whenever the trip device 8| is operated so as todump the pressure air to atmosphere and thereby permit quick opening ofthe circuit breaker. The air pressure exhaust means is fully disclosedin the aforementioned copending application Serial No. 410,686 andcomprises air pressure exhaust ports I23 formed in the side of theoperating cylinder 29 which are adapted to be connected to atmosphere bya main exhaust valve (not shown). The main exhaust valve isautomatically opened by theair pressure above the operating piston I03when a pilot valve I25 is opened in response to operation of the tripdevice 81. The exhaust ports I23 are of larger size than the compressedair inlet passage II2 so that the breaker will be opened quickly uponoperation of the trip device 8| even though the main inlet valve may beopen and admitting compressed air to the cylinder at the time the tripdevice is operated. Thus the breaker is trip free of the closing means.

The compressed air operating means is operable to produce normal closingoperations of the circuit breaker starting from the full open positionof the breaker. and is also operable to eiiect quick automatic reclosingoperations of thebreak er wherein the reclosing movement is initiated atan intermediate point in the opening stroke of the breaker after thecircuit is interrupted but before the breaker reaches full openposition. The control circuits for controlling the operation of theinlet valve electromagnet I I1 and the trip device 8I are preferably thesame as the control circuits disclosed in the aforementioned copendingapplication Serial No. 410,686. These control circuits have not beenshown in this application as they are unnecessary for a completeunderstanding of the present invention. It is believed 'sufiicient tostate that the tripping electromagnet 8| is energized in response to anoverload or short circuit in the main circuit, and also by a manual tripcontrol switch. For quick automatic reclosing operations. the inletvalve controlling electromagnet II! is automatically energized by anauxiliary switch at an intermediate point in the opening stroke of thebreaker to cause the inlet valve to admit compressed air to theoperating cylinder at this time. The auxiliary switch is adjustable sothat regular automatic reclosing operation from the full open positionmay be obtained if desired. The electromagnet II1 may also be energizedby a manual closing control switch to effect closing operation of thecircuit breaker from the full open position of the breaker. Referencemay be had to the aforementioned copending application, Serial No.410,686 for the details of the control circuits for accomplishing theabove operations.

An automatic throttle device is provided which is effective to throttlethe flow of compressed air to the operating cylinder a predeterminedamount during the first part of the closing stroke of the operatingpiston on closing operation of the circuit breaker started from the fullopen position, and which is automatically operated to an open ornon-throttling position during the latter portion of the closing stroketo permit compressed air to flow to the operating cylinder at anincreased rate during the final portion of the closing stroke.Compressed air is admitted relatively slowly by the throttle during thefirst part of the closing operation thus decreasing the tendency of theoperating mechanism to slam. A larger quantity of compressed air isadmitted to the operating cylinder by the throttle during the finalportion of the closing stroke thereby providing suflicient driving powerto overcome the relatively heavy contact load imposed by the contactpressure spring means during the final portion of the closing stroke.The throttle means is also constructed so that it will remain in wideopen position during the major portion of the opening stroke of theoperating piston and during quick reclosing operations, therebyadmitting the larger quantity of compressed air necessary to quicklyreverse the movement of the circuit breaker and quickly reclose thesame.

The automatic throttle means comprises a cylindrical piston shaped valveelement I31 slidably mounted in a vertically disposed cylindrical recessI33 which crosses the inlet air passage I I2 in the inlet valve housingI IS. A closure cap I35 is secured in the upper end of the cylindricalrecess I33 for closing the upper end of this recess. The valve elementI3I is threadedly mounted on the central portion of a rod I31 whichslidably extends in a fluid-tight manner through openings providedtherefor in the closure member I35 and in the bottom of the valvehousing H9. The valve element I3I is secured in mounted position on therod I31 by a retaining pin (not shown). The upper end of the rod I31 isthreadedly connected to a U-shaped connecting element I39, a lock nutI4l being provided to secure the connection. The valve element I3I isadapted to be actuated to a throttling position and to an open ornonthrottling position by a snap acting spring toggle comprising a pairof rods or links I43 and I45 having U-shaped rod ends I41 which arepivotally connected together and to the connecting element I39, by apivot pin I49 which forms the knee of the actuating toggle. The freeends of the toggle rods I43 and I45 slidably extend through enlargedopenings provided therefor in a pair of supporting arms II which aresecured to the closure member I35. A compression spring I53 is mountedon each toggle rod and disposed in compression between the rod head I41and supporting arm I5| of the rod.

The valve element I3I is adapted to be actuated to its throttlingposition shown in Fig. 1 during the latter part of the opening stroke ofthe breaker and operating piston, and actuated downwardly to its open ornon-throttling position during the latter portion of the closing strokeof the breaker operating piston. A link I55 is provided for the purposeof initiating the actuation of the valve element I3I at the proper time.The connecting link I55 is pivotally connected at its lower end to theknee of the actuating toggle by means of the pivot pin I49, and theupper portion of the link is provided with an elongated slot I51 whichengages a pin or stud I 59 projecting laterally from the breakeroperating lever 35. An adjusting screw IGI is threaded into the upperend of the link I55 and the lower end of this screw is adapted to extendinto the upper portion of the slot I51. The adjustment of the screw I6Idetermines the point in the opening stroke of the breaker operatingpiston at which actuation of the valve element I3I to its throttlingposition will be initiated. An adjustable collar I63 may be mounted onthe link I55 adjacent the lower end of the slot I51 to determine thepoint at which actuation of the valve element I3I to its open positionwill be initiated.

Adjustment of the throttling position, that is, the degree of throttlingof the valve I3I is accomplished by means of a pair of lock nuts I65which are threaded on the extending lower end of the valve rod I31.These lock nuts act as an adjustable stop to determine the upper orthrottling position of the valve element I3I. Adjustment of the open ornon-throttling position of the valve element I3I is accomplished bymeans of a pair of lock nuts I61 which are threaded on the upper portionof the valve rod I31. These look nuts I61 limit the amount of downwardmovement of the valve element I3I and thus determine the size of the airopening provided in the open position of the valve element I3I. Theinlet air passage H2 is of general triangular shape, as shown by thedotted lines in Fig. 2, so as to provide for a maximum range ofadjustment of the throttle opening provided by the valve element I3I inthe throttle position thereof. In the position of the parts shown inFigs. 1 and 2, the valve element I3I provides a relatively high degreeof throttling since only the apex of the triangular shaped inlet passageII 2 is uncovered by the valve element in the throttling positionthereof. If the lock nuts I65 are backed off, the size of the throttleopening will be increased and if the lock nuts are screwed upwardly onthe rod the size of the throttle opening will be decreased.

The operation 'of the mechanism is briefly as follows: When the circuitbreakeris in the full open position, as shown in Fig. 1. the throttlevalve element I3I is maintained in the throttlin position as shown, inwhich it will act to throttle the flow of compressed air to the upperend of the cylinder a predetermined amount. To close the circuitbreaker, the inlet valve controlling electromagnet H1 is energized.Energization of the electromagnet I I 1 opens the pilot valve I I5 andthereby causes opening of the main inlet valve I2I. Upon opening of themain inlet valve I2I compressed air flows through the in let passage II2 into the upper end of the operating cylinder 29 and moves theoperating piston I03 downwardly to closed position to effect closing ofthe circuit breaker. During the first part of the closing stroke, thethrottle valve I3I is maintained in throttling position in which itthrottles the flow of compressed air to the cylinder a predeterminedamount admitting air to the operating cylinder relatively slowly.Shortly before the contacts of the circuit breaker touch, the projectingpin I59 will engage the bottom of the slot I'I in the link I55 andthereby initiate actuation of the throttle valve I3I to its openposition. As soon as the knee pin I49 of the actuating toggle is moveddownwardly through the dead-center position, the spring toggle actuatesthe valve element I3I downwardly to its open position with a snapaction, thus the valve element I3I is actuated to open throttle positionduring the latterportion of the closing stroke of the breaker operatingpiston and allows the compressed air to flow at an increased rate intothe operating cylinder and thereby provide a relatively large drivingforce during the final portion of the closing stroke of the operatingpiston. When the circuit breaker reaches the fully closed position, thelatching roller 4! is engaged under the mainlatch 5| and the breaker isheld latch closed by the latching mechanism. As soon as the breakerreaches the fully closed position, the valve controlling electromagnetII! is deenergized and the main inlet valve I2I returns to closedposition shutting off the flow of compressed air to the operatingcylinder 29.

If an overload or short circuit occurs in the circuit controlled by thecircuit breaker, the trip device 8| will be immediately energized andthe trip plunger 79 thereof quickly moved upwardly to effect release ofthe latching mechanism and at the same time opening of the exhaust pilotvalve I25. The release of the latching mechanism comprising theauxiliary latch 61 and main latch 5| permits the circuit breaker to bemoved quickly to open position by its accelerating spring I5. Theopening of the exhaust pilot valve I will cause the main exhaust valveto open if there is any substantial air pressure in the operatingcylinder above the piston I03, to thereby dump the air to atmospherethrough the exhaust ports I23.

If the circuit breaker is set for quick automatic reclosing operation,the inlet valve controlling electromagnet II"! will be automaticallyenergized early'in the opening stroke of the circuit breaker therebycausing the inlet valve I2I to open and admit compressed air to theoperating cylinder during the opening movement. The throttle valve I3Iremains in the open or nonthrottling positionduring the major portion ofthe opening stroke and hence will be in open position at the timecompressed air is admitted for quick reclosing and will remain openduring the quick reclosing operation. 5 This is due to the length of theslot I51 in the connecting link I55. Sincethe throttle valve I 3 If isin the open throttle position a large quantity of compressed air will beadmitted to the operating cylinder and the compressed air will quicklyreverse the movement of the operating piston and initiate the reclosingmovement of the operating piston at an intermediate point in the openingstroke before the circuit breaker reaches full open position. Thereclosing movement proceeds and if the fault or overload condition whichcaused the initial opening, has been cleared, the circuit breaker willbe driven to the fully closed position and relatched. The inlet valvecontrolling electromagnet I I 7 will be deenergized and the inlet valveI2I returned to closed position when the breaker reaches the fullyclosed and latched position. However, if the overload or fault conditionis still present at the time the circuit breaker contacts reach thetouch position during the reclosing movement, the trip device 8I will beimmediately energized in. response to the overload condition and willretrip the breaker by releasing the latching mechanism andsimultaneously opening the exhaust pilot valve I25. The opening of theexhaust pilot valve I25 will cause the main exhaust valve to open anddump the closing air from the operating cylinder to atmosphere so thatit will not retard the opening movement of the circuit breaker.

The circuit breaker ma be manually tripped by means of the manual tripcontrol switch which effects energization of the trip device 8!. Thecircuit breaker will be moved quickly to the full open circuit positionand during the latter part of the opening movement shortly before thebreaker reaches its full open position, the projecting pin 59 on thebreaker operating lever 35 will engage the adjusting screw IBI adjacentthe end of the slot I51 and initiate actuation of the throttle valveelement I3I to its throttlin position shown in Fig. 1. The snap actiontoggle will thereby be caused to move to its upper overcenter positionshown moving the valve with a snap action to its throttling position.The mechanism is now ready for a normal closing operation.

From the foregoing, it will be seen that the automatic throttle valveI3l causes the flow of compressed air to the operating cylinder to. be

throttled a predetermined amount during the first part of each closingoperation started from full open position, and the throttle valve isautomatically opened during. the latter part of the closing stroke ofthe operating piston thereby admitting a large quantity of air to theupper side of the operating piston during the final portion. of theclosing stroke. The throttle valve remains in the open throttle positionduring the major portion of the opening stroke of the operatin pistonand during quick-reclosing operations, due to the elongated slot I51 inthe connecting link I55, so that an increased quantity of air will beadmittedv to the operating cylinder on quick reclosing operations.

The compressed air circuit breaker operating means as thus far describedin detail above is the same as disclosed in the aforementioned copendingapplication of H. L. Peek, Serial No. 445,733,. and the same referencecharacters have been used to designate the corresponding parts. In somecases quick (fractional stroke) automatic reclosing may not be desired.In such instance the auxiliary switch (not shown but disclosed in theaforementioned copendin application of J. M. Cumming and R. C.Cunningham Serial No. 410,686) which effects energization of the inletvalve controlling electromagnet I I1 and initiates the reclosingoperation, may be adjusted to close when the breaker reaches the fullopen position so that automatic reclosing movement of the breaker willbe initiated shortly after the breaker reaches the full open position.In this instance the automatic throttle valve functions in the samemanner as on normal closing p tion as previously described.

In accordance with the present invention a means is provided, responsiveto the pressure of the air in the air reservoir III, for automaticallychanging the size of the throttle opening provided by the automaticthrottle valve as the pressure of the air in the reservoir changes. Thepressure responsive device serves to automatically open the throttlevalve wider as the pressure in the reservoir decreases, and returns thethrotthe valve to the normal throttle position when the air pressure inthe reservoir is returned to normal.

Referring to the drawing the pressure responsive device comprises anannular expandable and contractable metal bellows I1I disposed in acircular recess I13 in the bottom of the valve housing H9. The bellowsis secured to a closure plate I15 which is in turn secured to the valvehousing over the bottom of the recess I13. A movable sleeve shaped stopmember I11 is slidably mounted on the throttle valve rod I31 in therecess I13, the lower end of the stop member slidably extending throughan opening provided in the bottom closure plate I15. The upper end ofthe member I11 has a circular flange I19 the under side of which isrigidly secured to the top of the annular metal bellows I1I so that thestop member is movable by the bellows. The bellows is constructed ofresilient material and formed so that it normally tends to assume acollapsed position due to the resiliency of the material and thecorrugated shape of the bellows. A small diameter pipe IBI connects theinterior chamber of the bellows to the interior of the compressed airreservoir III so that the bellows, which is of air tight construction,is thus made responsive to the pressure in the air reservoir III.

The lower end of the sleeve shaped stop member I11 is engageable by thelock nuts I65 on the lower end of the throttle valve rod I31 and thusacts as a movable stop to limit the upward movement of the throttlevalve and thereby determine the throttling position of the valve andhence the size of the throttle opening for any given adjustment of thelock nuts I65.

As previously described a supply of compressed air is maintained in theair reservoir III at a predetermined normal pressure from a largereservoir tank supplied by a conventional automatic compressor unit (notshown). The normal air pressure will depend of course on the size of themechanism, for example, an air reservoir pressure of 150 pounds persquare inch has been found suitable for a mechanism having an 8 inchdiameter piston. With the normal air pressure in the tank III, the locknuts I65 are initially adjusted to give the proper size throttle openingso that the mechanism will not slam on closing operations started fromthe full open position, and the lock nuts I61 are adjusted so that anample quantity of air will be admitted during the latter portion of theclosing stroke, and for quick reclosing operations if quick reclosing isdesired.

It the air pressure in the reservoir III decreases any substantialamount from the normal value, due to some defect or failure of thecompressor, the pressure responsive bellows contracts proportionally andmoves the stop member I11 downwardly as the pressure decreases. Thismovement of the stop member is transmitted through the lock nuts I65 andthe valve rod I31 causing downward movement of the throttle valve I3Ithereby increasing the size of the throttle opening. Thus the valve I3Iis opened wider as the air pressure in the reservoir decreases therebyadmitting compressed air at a faster rate at the lowered pressure thanit does at higher pressures. As a result the speed of operation of themechanism is maintained substantially constant despite a decrease inavailable air pressure. As the pressure builds back up to normal valuethe bellows expands and allows the throttle valve I3I to be returned bythe spring toggle to its normal throttling position. The device will notonly tend to maintain the normal operating speed but it will alsoincrease the number of operation possible at a given reservoir pressure.

While the invention has been disclosed in accordance with the provisionsof the Patent Statutes, it is to be understood that various changes inthe structural details and arrangement of parts may be made withoutdeparting from some of the essential features of the invention. It isdesired, therefore, that the language of the appended claims be giventhe broadest reasonable interpretation permissible in the light of theprior art.

We claim as our invention:

1. In combination, a circuit breaker, compressed gas operating mechanismfor operating said circuit breaker, a gas pressure supply system forsupplying compressed gas to actuate said operating mechanism, means forcontrolling the rate of flow of compressed gas to said mechanism,actuating means for said rate controlling means controlled in responseto predetermined movements of said circuit breaker, and pressureresponsive means connected to said supply system for automaticallycontrolling said first mentioned means in response to changes in gaspressure of said supply system.

2. In combination, a circuit breaker, compressed gas operatin mechanismfor operating said breaker, a gas pressure supply system for supplyingcompressed gas to actuate said operating mechanism, means including avariable orifice means controlled by predetermined movement of saidcircuit breaker for controlling the rate of flow of gas to saidoperating mechanism, and pressure responsive means connected to said gaspressure supply system for automatically increasing the flow area ofsaid variable orifice means in response to reduction in gas pressure ofsaid supply system.

3. In combination, a circuit breaker, compressed gas operating mechanismfor operating said circuit breaker, a gas pressure supply system forsupplying compressed gas to actuate said operating mechanism, meanscomprising a valve for automatically controlling the rate of flow ofcompressed gas to said operating mechanism in response to predeterminedoperations of said mechanism, a movable stop member for determining oneof the positions of said valve, and pressure responsive means connectedto said supply system for automatically moving said stop member inresponse to changes in pressure of said supply system.

4. A circuit breaker operating means of the compressed air typecomprising a cylinder, a piston in said cylinder for operating thebreaker, an air pressure supply system for supplying compressed air toactuate said piston, means including an automatic valve for controllingthe rate of flow of compressed air to said cylinder, actuating means forsaid valve controlled in response to predetermined movements of saidbreaker and means movable in response to changes in the air pressure ofsaid supply system for controlling the position of said valve.

5. In combination, a circuit breaker movable to open and to closedcircuit position, compressed gas operating mechanism for operating saidbreaker to closed circuit position, a gas pressure supply system forsupplying compressed gas to said operating mechanism to effect closingof said circuit breaker, means including an automatic valve forcontrolling th rate. of flow of compressed gas to said operatingmechanism, actuating means for said valve operable to actuatesaid valvefrom one position to anopen position during the latter part of a closingstroke of said op-v erating mechanism started from fulllopen position ofthe breaker, and means responsiveto the gas pressure of said supplysystem for auto.-

maticallychanging the flow area in said one position of said valve inresponse to changes ing'as pressure of said supply system.

6. In combination, a circuit breaker movable to open and to closedcircuit position, compressed gas operating mechanism for operating saidbreaker to closed circuit position, a gas pressure supply system forsupplying compressed gas to said operating mechanism to operate thbreaker, means including an automatic valve for controlling the rate offlow of compressed gas to said operating mechanism, actuating means forsaid valve operable to actuate said valve from one position to an openposition during the latter portion of a closing stroke of said mechanismstarted from full open position of the breaker, and operable to actuatesaid valve to said one position during the latter portion of the openingstroke of the operating mechanism, and pressure responsive meansconnected to said suppl system for automatically moving said valve inopening direction in response to decrease in air pressure of said supplysystem.

7. In combination, a circuit breaker movable to open and to closedcircuit position, compressed gas operating mechanism for operating saidbreaker to closed circuit position, a gas pressure supply system forsupplying gas to said mechanism to close the breaker, means including anautomatic valve for controlling the rate of flow of compressed gas tosaid mechanism, actuating means for said valve controlled in response topredetermined movements of the breaker and perable at times toautomatically actuate said valve from one position to an open positionindependently of changes in pressure in said supply system, and meansmovable in response to reduction in gas pressure of a portion of saidsupply system for automatically actuating said valve toward openposition to insure an adequate rate of supply of compressed gas tooperate said mechanism.

8. In combination, a circuit breaker movable to open and to closedcircuit position, compressed gas Operating mechanism for operating saidbreaker to closed circuit position, a gas pressure supply system forsupplying compressed gas to said mechanism to close the breaker, anautomatic throttle valve for controlling the rate of flow of compressedgas to said mechanism, actuating means for said valve controlled by saidcircuit breaker operating mechanism, said valve actuating meansoperating at times to automatically actuate said valve from a throttlingposition to a wide open position, and pressure responsive meansconnected to said supply system for automatically changing thethrottling posi-- tion of said valve in response to changes in gaspressure of said supply system.

9. In combination, a circuit breaker movable to open and to closedcircuit position, compressed gas operating mechanism for operating saidbreaker to closed circuit position, a gas pressure supply system forsupplying compressed gas to said mechanism to close the breaker, anautomatic throttle valve for controlling the rate of flow of compressedgas to said mechanism, actuating means for said valve operable inresponse to predetermined movements of said breaker to automaticallyactuate said valve from a throttling position to a wide open position,and pressure re-, sponsive means connected to said supply system forautomatically increasing the throttle opening provided by said valve inresponse to decrease ingas pressure of said supply system.

10. In combination, a circuit breaker, compressed gas operatingmechanism operable to close the breaker, a compressed gas supply systemfor supplying gas under pressure to said mechanism to operate themechanism, means operative to admit compressed gas to said mechanism fora portion of said supply system at a predetermined rate during the firstpart of the closing stroke of the mechanism and at an increased .rateduring the latter portion of the closing stroke, and means responsive toa decrease in gas pressure in said portion of the supply system toautomatically provide for admitting compressed gas to said mechanism ata rate that is greater than would be obtained from said portion of thesupply at the reduced pressure in the absence of said pressureresponsive means.

11. A compressed gas operating mechanism for a circuit breakercomprising an operating cylinder, a piston in said cylinder foroperating the breaker, a compressed gas supply system for supplying gasunder pressure to said cylinder to operate said piston, means operativein response to predetermined movements of said breaker to at timeschange the rate at which gas under pressure is supplied to saidcylinder, and means responsive to a, decrease in ga pressure in saidsupply system to automatically provide for an increased rate of flow ofcompressed gas to said cylinder over that which would be obtained fromthe supply system at reduced pressure.

12. In combination, a circuit breaker, compressed gas operating meansfor operating said circuit breaker, a compressed gas supply system forsupplying gas to said mechanism to operate the breaker, means forautomatically controlling the rate of flow of gas to said mechanism inresponse to predetermined movements of said circuit breaker, and meansresponsive to changes in gas pressure in a portion of said-supply systemfor automatically changing the rate at which compressed gas will besupplied to said mechasaid circuit breaker, a compressed gas supplysystem for supplying gas under pressure to said mechanism to operate thebreaker, means for controlling the flow of compressed gas to saidmechanism including means operative in response to predeterminedmovements of said breaker for at times changing the rate at which gas issupplied to said mechanism, and means responsive to a decrease in gaspressure in a portion of said supply system for providing for anincreased supply of gas to said operating means over what would beobtained from said portion of the system at decreased pressure.

14. In combination, a circuit breaker, compressed gas operatingmechanism for operating said circuit breaker, a compressed gas supplysystem for supplying gas under pressure to said mechanism to operate thebreaker, means for controlling the flow of compressed gas to saidcylinder including means operative in response to predeterminedmovements of said breaker for at times changing the rate at which gas issupplied to said cylinder, and means responsive to changes in gaspressure in a portion of said compressed gas supply system forautomatically controlling the flow of compressed gas to said operatingmechanism to cause substantially the same driving force to be applied tosaid mechanism as when the pressure of said portion of the supply systemwas at normal value.

15. In a fluid pressure operated mechanism for a circuit breaker, incombination, operating means including a cylinder having a pistonmounted therein for closing said breaker, a source of supply of fluidunder pressure, means including a communication connecting said sourceto said cylinder, throttling valve means interposed in saidcommunication and operative upon occurrence of a given condition forrestricting the flow of fluid to said cylinder, and means responsive tothe pressure of fluid in said supply source for rendering saidthrottling valve ineffective to restrict said supply communication.

16. In a fluid pressure operated mechanismfor a circuit breaker, incombination, operating means including a cylinder having a pistonmounted therein for closing said breaker, a source of supply of fluidunder pressure, means including a communication connecting said sourceto said cylinder, throttling valve means interposed in saidcommunication and operative upon occurrence of a given condition forrestricting the flow of fluid to said cylinder, and means operative upona predetermined decrease in the pressure of fluid in said supply sourcefor rendering said throttling valve ineffective to restrict said sup plycommunication.

HENRY L. PEEK.

JAMES M. CUMMING.

